[alsa-devel] [PATCH 04/12] ALSA: oxfw: share PCM buffer size for both direction

[Takashi Sakamoto]

This commit allows ALSA oxfw driver to share PCM buffer size for both
capture and playback PCM substream. When AMDTP domain starts for one
of the PCM substream, buffer size of the PCM substream is stores to
AMDTP domain structure. Some AMDTP streams have already run with the
buffer size when another PCM substream starts, therefore the PCM
substream has a constraint to its buffer size.

Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
 sound/firewire/oxfw/oxfw-midi.c   |  4 ++--
 sound/firewire/oxfw/oxfw-pcm.c    | 17 +++++++++++++++--
 sound/firewire/oxfw/oxfw-stream.c |  5 +++--
 sound/firewire/oxfw/oxfw.h        |  3 ++-
 4 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/sound/firewire/oxfw/oxfw-midi.c b/sound/firewire/oxfw/oxfw-midi.c
index 72db7a17d0ad..775cba3f1f02 100644
--- a/sound/firewire/oxfw/oxfw-midi.c
+++ b/sound/firewire/oxfw/oxfw-midi.c
@@ -18,7 +18,7 @@ static int midi_capture_open(struct snd_rawmidi_substream *substream)
 
 	mutex_lock(&oxfw->mutex);
 
-	err = snd_oxfw_stream_reserve_duplex(oxfw, &oxfw->tx_stream, 0, 0, 0);
+	err = snd_oxfw_stream_reserve_duplex(oxfw, &oxfw->tx_stream, 0, 0, 0, 0);
 	if (err >= 0) {
 		++oxfw->substreams_count;
 		err = snd_oxfw_stream_start_duplex(oxfw);
@@ -45,7 +45,7 @@ static int midi_playback_open(struct snd_rawmidi_substream *substream)
 
 	mutex_lock(&oxfw->mutex);
 
-	err = snd_oxfw_stream_reserve_duplex(oxfw, &oxfw->rx_stream, 0, 0, 0);
+	err = snd_oxfw_stream_reserve_duplex(oxfw, &oxfw->rx_stream, 0, 0, 0, 0);
 	if (err >= 0) {
 		++oxfw->substreams_count;
 		err = snd_oxfw_stream_start_duplex(oxfw);
diff --git a/sound/firewire/oxfw/oxfw-pcm.c b/sound/firewire/oxfw/oxfw-pcm.c
index f3e25898d270..ba586d1ac91d 100644
--- a/sound/firewire/oxfw/oxfw-pcm.c
+++ b/sound/firewire/oxfw/oxfw-pcm.c
@@ -188,6 +188,7 @@ static int pcm_open(struct snd_pcm_substream *substream)
 	// at current one.
 	if (oxfw->substreams_count > 0 && d->events_per_period > 0) {
 		unsigned int frames_per_period = d->events_per_period;
+		unsigned int frames_per_buffer = d->events_per_buffer;
 
 		err = limit_to_current_params(substream);
 		if (err < 0) {
@@ -203,6 +204,14 @@ static int pcm_open(struct snd_pcm_substream *substream)
 				mutex_unlock(&oxfw->mutex);
 				goto err_locked;
 			}
+
+			err = snd_pcm_hw_constraint_minmax(substream->runtime,
+					SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
+					frames_per_buffer, frames_per_buffer);
+			if (err < 0) {
+				mutex_unlock(&oxfw->mutex);
+				goto err_locked;
+			}
 		}
 	}
 
@@ -239,10 +248,12 @@ static int pcm_capture_hw_params(struct snd_pcm_substream *substream,
 		unsigned int rate = params_rate(hw_params);
 		unsigned int channels = params_channels(hw_params);
 		unsigned int frames_per_period = params_period_size(hw_params);
+		unsigned int frames_per_buffer = params_buffer_size(hw_params);
 
 		mutex_lock(&oxfw->mutex);
 		err = snd_oxfw_stream_reserve_duplex(oxfw, &oxfw->tx_stream,
-					rate, channels, frames_per_period);
+					rate, channels, frames_per_period,
+					frames_per_buffer);
 		if (err >= 0)
 			++oxfw->substreams_count;
 		mutex_unlock(&oxfw->mutex);
@@ -265,10 +276,12 @@ static int pcm_playback_hw_params(struct snd_pcm_substream *substream,
 		unsigned int rate = params_rate(hw_params);
 		unsigned int channels = params_channels(hw_params);
 		unsigned int frames_per_period = params_period_size(hw_params);
+		unsigned int frames_per_buffer = params_buffer_size(hw_params);
 
 		mutex_lock(&oxfw->mutex);
 		err = snd_oxfw_stream_reserve_duplex(oxfw, &oxfw->rx_stream,
-					rate, channels, frames_per_period);
+					rate, channels, frames_per_period,
+					frames_per_buffer);
 		if (err >= 0)
 			++oxfw->substreams_count;
 		mutex_unlock(&oxfw->mutex);
diff --git a/sound/firewire/oxfw/oxfw-stream.c b/sound/firewire/oxfw/oxfw-stream.c
index 318de8217b3a..995e9c5bd84b 100644
--- a/sound/firewire/oxfw/oxfw-stream.c
+++ b/sound/firewire/oxfw/oxfw-stream.c
@@ -245,7 +245,8 @@ static int keep_resources(struct snd_oxfw *oxfw, struct amdtp_stream *stream)
 int snd_oxfw_stream_reserve_duplex(struct snd_oxfw *oxfw,
 				   struct amdtp_stream *stream,
 				   unsigned int rate, unsigned int pcm_channels,
-				   unsigned int frames_per_period)
+				   unsigned int frames_per_period,
+				   unsigned int frames_per_buffer)
 {
 	struct snd_oxfw_stream_formation formation;
 	enum avc_general_plug_dir dir;
@@ -308,7 +309,7 @@ int snd_oxfw_stream_reserve_duplex(struct snd_oxfw *oxfw,
 		}
 
 		err = amdtp_domain_set_events_per_period(&oxfw->domain,
-							frames_per_period, 0);
+					frames_per_period, frames_per_buffer);
 		if (err < 0) {
 			cmp_connection_release(&oxfw->in_conn);
 			if (oxfw->has_output)
diff --git a/sound/firewire/oxfw/oxfw.h b/sound/firewire/oxfw/oxfw.h
index 422746ef2439..c30e537087b0 100644
--- a/sound/firewire/oxfw/oxfw.h
+++ b/sound/firewire/oxfw/oxfw.h
@@ -104,7 +104,8 @@ int snd_oxfw_stream_init_duplex(struct snd_oxfw *oxfw);
 int snd_oxfw_stream_reserve_duplex(struct snd_oxfw *oxfw,
 				   struct amdtp_stream *stream,
 				   unsigned int rate, unsigned int pcm_channels,
-				   unsigned int frames_per_period);
+				   unsigned int frames_per_period,
+				   unsigned int frames_per_buffer);
 int snd_oxfw_stream_start_duplex(struct snd_oxfw *oxfw);
 void snd_oxfw_stream_stop_duplex(struct snd_oxfw *oxfw);
 void snd_oxfw_stream_destroy_duplex(struct snd_oxfw *oxfw);
-- 
2.20.1